automatic/modules/sd_samplers_timesteps.py

74 lines
2.5 KiB
Python

# TODO a1111 compatibility module
import torch
from modules import sd_samplers_common, sd_samplers_timesteps_impl, sd_samplers_compvis
from modules.sd_samplers_cfg_denoiser import CFGDenoiser
import modules.shared as shared
samplers_timesteps = [
('DDIM', sd_samplers_timesteps_impl.ddim, ['ddim'], {}),
('PLMS', sd_samplers_timesteps_impl.plms, ['plms'], {}),
('UniPC', sd_samplers_timesteps_impl.unipc, ['unipc'], {}),
]
samplers_data_timesteps = [
sd_samplers_common.SamplerData(label, lambda model, funcname=funcname: VanillaStableDiffusionSampler(funcname, model), aliases, options)
for label, funcname, aliases, options in samplers_timesteps
]
class CompVisTimestepsDenoiser(torch.nn.Module):
def __init__(self, model, *args, **kwargs):
super().__init__(*args, **kwargs)
self.inner_model = model
def forward(self, input, timesteps, **kwargs): # pylint: disable=redefined-builtin
return self.inner_model.apply_model(input, timesteps, **kwargs)
class CompVisTimestepsVDenoiser(torch.nn.Module):
def __init__(self, model, *args, **kwargs):
super().__init__(*args, **kwargs)
self.inner_model = model
def predict_eps_from_z_and_v(self, x_t, t, v):
return self.inner_model.sqrt_alphas_cumprod[t.to(torch.int), None, None, None] * v + self.inner_model.sqrt_one_minus_alphas_cumprod[t.to(torch.int), None, None, None] * x_t
def forward(self, input, timesteps, **kwargs): # pylint: disable=redefined-builtin
model_output = self.inner_model.apply_model(input, timesteps, **kwargs)
e_t = self.predict_eps_from_z_and_v(input, timesteps, model_output)
return e_t
class CFGDenoiserTimesteps(CFGDenoiser):
def __init__(self, sampler):
super().__init__(sampler)
self.alphas = shared.sd_model.alphas_cumprod
self.mask_before_denoising = True
self.model_wrap = None
def get_pred_x0(self, x_in, x_out, sigma):
ts = sigma.to(dtype=int)
a_t = self.alphas[ts][:, None, None, None]
sqrt_one_minus_at = (1 - a_t).sqrt()
pred_x0 = (x_in - sqrt_one_minus_at * x_out) / a_t.sqrt()
return pred_x0
@property
def inner_model(self):
if self.model_wrap is None:
denoiser = CompVisTimestepsVDenoiser if shared.sd_model.parameterization == "v" else CompVisTimestepsDenoiser
self.model_wrap = denoiser(shared.sd_model)
return self.model_wrap
VanillaStableDiffusionSampler = sd_samplers_compvis.VanillaStableDiffusionSampler